Overview

The two IP-PBX design categories, converged and client/server, are based on very different architecture platforms. Individual product models within both categories also exhibit different design architectures. Just as no two circuit switched PBX systems are based on identical call processing, switching, and common equipment topologies and constructs, no two IP-PBX system models have the same design attributes. The IP telephony hardware options of a converged IP-PBX system are influenced by the basic design of the circuit switched platform on which it is based. Beyond total dependency on a LAN/WAN infrastructure for all switching and transport, currently available client/server IP-PBXs have sufficiently unique design attributes to easily distinguish themselves from competitive offerings. Support of IP control signaling and packeted voice communications is sometimes the only common thread between many of the IP-PBX systems currently being marketed to the public.

A converged IP-PBX system design is based on a traditional circuit switched design platform that supports analog and digital ports with a TDM/PCM transmission and voice coding format. What distinguishes a converged IP-PBX system from a traditional PBX system is the integration of ToIP technology to support call control or voice communications signaling. Signaling is packeted by using IP format, and voice coding may or may not involve compression of the 64-Kbps PCM sample traditionally used to digitize analog voice waveforms.

Converged IP-PBXs can include any or all of the following system design attributes:

1. Integrated support of IP station ports

2. Integrated support of VoIP trunking

3. Integrated support of...